Looper mechanism for sewing-machines.



A. H. DE VOE.

LOOPER MECHANISM FOR SEWING MACHINES.

APPLICATION FILED DEC. 1. 1916.

1,299,402. Patnted Apr. 1,1919.

WITNESS: INVENTOR TORNEY TED s rn'rns rn'rnn'r orricn.

ALBERT H. DE VOE, OF WES'ITIELD, NEW JERSEY, ASSIGNOR TO THE SINGERMANUFACTURING COMPANY, A CORPORATION OF NEW JERSEY.

LOO PER MECHANISM FOR SEWING-MACHINES.

Specification of Letters Patent.

Application filed December 1, 1916, Serial 'No. 134,254.

of New Jersey, have invented certain new and useful Improvements inLooper Mechanisms for Sewing-Machines, of which the following is aspecification, reference being had therein to the accompanying drawings.

This invention relates to asewing machine of the class employing athread-carrying looper which cooperates with a needle in making a doublechain-stitch.

To facilitate the threading up of a threadcarrying looper it isconvenient to have means of some sort affording access to the eyestherein. A device which afi'ords access to loopers is shown in my priorPatent No. 1,256,880, issued February 19-, 1918. In said patent thethread-carrying loopers were withdrawn from their rearmost retractedposition to a position nearer the operator and spaced farther from thethroat-plate. The finger-lever at the end of the machine for effectingthis withdrawal of the looper was locked against movement excepting whenthe looper was in its rearmost retracted position by means of adetent-pin engageable with a recess in a disk fast on the mainshaft.

In said device it was necessary to turn the main-shaft to a certainposition in a stitching cycle and by constantly pulling upon thefinger-lever to feel for the recess in the disk on the main-shaft inwhich the detent-pin could be forced and held by movement of.

improve the above mentioned construction bv facilitating the finding ofthe position in which the pin and recess register, while retainingsubstantially all of the advantages of the old construction. This hasbeen accomplished by mounting the segmental plate of the oldconstruction for bodily movement in the direction of the axis of thedetent-pin. V

Briefly the construction may be described as comprising a fulcrum-shafteccentric of bearing bosses journaled in the frame of the machine to oneof which is secured a fingerlever carrying a segmental-plate having inone face a pocket adapted to permit .a detentpin under the thrust of acoiled spring being held in a position clear of a recess in a disk onthe main-shaft of'the machine, said segmental plate having a pinprojecting from its other face which has a limited sliding movement in aboss carried by the lever and pocketing a-spring of greater strengththan-the spring about the detent-pin, thus urging the segmental plate ina direction opposite to that in which the detent-pin is urged by itscoiled spring.

The invention also consists in further de- Patented Apr. 1, 1919. I

tails of construction that will appear from the following description ofthe embodiment of the invention illustrated in the accompanyingdrawings, in which Figures-1 and 2 are perspective views of the device,respectively, in working relation and in detail partly in section.

The invention is applicable to either a single ormultiple-needlestitching mechanism. It is shown applied to a multipleneedle machine andexcepting the segmental plate is the same in its essential details ofconstruction as that found in my previously mentioned patent. Brieflyneedles 1 cooperate with loopers 2 actuated. by an inclined crank 3 onthe main-shaft 4 to which suitable thrust flanges or disks 5 and 6 arefixedly connected at opposite ends of the crank. In the left-hand disk 5near its periphery a recess 7 is provided for a purpose to be describedlater. Embracing the inclined crank 3 is a strap 8 at one end of a-pitman 9 whose other end is connected by a at the rear ends thereof,are given endwise position, the boss 13-of the fulcrum-shaft 12 isrotated by a finger-lever 20 secured thereto by a set-screw 21 in thehub 22of the lever. Shifting the lever'2O from a horizontal to avertical position results in moving the fulcrum shaft 12 about the axisof boss 13 through an angle of'approximately 90 thereby lowering andretracting the loopers from their normal cyclical paths of movement. Inthe inner face of a segmental plate 23 carried by the lever is provideda pocket 24 adapted to permit a detent pin 25 under the thrust of acoiled spring 26 to be held in a position clear of the recess 7 in thedisk 5 integral or fast on the main-shaft of the machine, when'thefinger-lever is in substantially a horizontal position. Projecting fromthe outer face of the segmental plate .is a pin 27 which slides in aboss 28 integral with the finger-lever, said pin having a fiat head 29which is adapted to limit the inward movement of the segmental plateaway from its seat 30 on the finger-lever. In the boss 28 is pocketed aspring 31 of greater strength than the spring 26 coiled about thedetent-pin 25 that urges the segmental plate in a direction opposite tothat in Which the detent pin is urged by its coiled spring. The

length of the slide-pin 27 is such that when the finger-lever is in ahorizontal position the spring 31 in the boss cannot move the segmentalplate a sufficient distance in overcoming the spring coiled about thedetent pin which is at this time seated in the pocket 24 to move thedetent-pin into the disk-recess 7 should it happen to be in registerwith the pin. But when the finger-lever has been moved from a horizontalor normal position throwing the end of the detent-pin out of the pocket24 the movement of the segmental plate under the action of the spring 31in the boss is suflicient to forcethe end of the pin into therecess inthe disk when said recess is brought into register with the pin byturning the main-shaft 4.

In operation the main-shaft is first turned to a position in which theloopers are near their retracted position when the detent pin and therecess in the disk of the main-shaft will be somewhere near aregistering position, the finger-lever is thrown out of its normalhorizontal position, and finally the main-shaft is manipulated until thedetent pin snaps into locking relation with the disk on the main-shaftunder the dominating action ofthe relatively strong spring carried bythe boss integral with the finger-lever. To unlock the main-shaft thefinger-lever'is merely thrown to a horizontal position when I thedetent-pin snaps back into the socket of the segmental plate out of therecess in the disk on the main-shaft. It will thus be seen that the oldconstruction of the previously mentioned patent has been improved byenabling the operator to readily find the position of the machine inwhich it is locked and in which the loopers may be most readilythreaded.

Having thus set forth the nature of the invention, what I claim hereinis 1. In a sewing machine, in combination, a reciprocating needle, alooper, actuating means for imparting operative movements to said needleand looper, means whereby saidlooper may be shifted from normaloperative position .to a position favoring easy threading thereof andoperable during at least a considerable part of a stitch-forming cycle,and means acting to lock said actuating means against movement at apredetermined period in a stitch-forming cycle. 2. In a sewing machine,in combination, a reciprocating needle, a looper, actuating means forimparting operative movements to said needle and looper, means wherebysaid looper may be shifted from normal operative position to a positionfavoring easy threading thereof, means acting to lock said actuatingmeans against movement at a predetermined period in stitching cycle andmeans permitting the shifting of the looper from its normal path at aplurality of periods in a stitching cycle. v

3. In a sewing machine comprising, in combination, a work-support, areciprocating needle, a looper, actuating means for imparting cyclicaloperative movements to sald needle and looper, means for locking saidactuating means operative only at a given time during the cycle ofoperation, and means for shifting said looper to an abnormal position atany time during a cycle of'operation.

4. In a sewing machine, in combination, a main-shaft,a reciprocatingneedle, a movable looper cooperating with said needle, a looper-support,actuating connections between said main-shaft and said looper-support,means whereby said looper-support may be moved from normal to abnormalposition, shiftable means for so moving said looper-support, connectionsbetween said shiftable means and said main-shaft for locking the latteragainst rotation when said looper is in easy threading position andincluding means actuating the locking connections to prevent operationof the machine when the main-shaft arrives at a predetermined position.

5. In a sewing machine, in combination with stitch-forming mechanismcomprising a needle, looper and actuating means therewhen the looper hasbeen moved from its normal path.

6. A sewing machine looper mechanism comprising .a looper, a carriertherefor, a

' supporting fulcrum upon which said carrier is adapted to performrocking movements, an actuating shaft and a rotary actuating elementthereon for said looper, an

operative connection between said element and said earner, andmeansoperative independent'ly of said actuating shaft for shifting saidsupporting fulcrum toward and from said actuating element at any timduring a stitching cycle.

7. A sewing mach'ne looper mechanism comprising a looper, a carriertherefor, a

supporting fulcrum upon which said carrier is adapted to perform rockingmovements, a rotary actuating element for said looper,

' said element and the said carrier, shifting means operative duringseveral degrees of a stitching cycle for retracting and returning saidsupporting fulcrum from and into normal operative relationwith saidactuating element,- and means for locking said acplate lever.

an operative connection between tuating element against turning whilethe fulcrum is out of normal relation therewith.

9. In a sewing machine, in combination with stitch-forming mechanismcomprising a needle and looper, actuating means for said looper, meansfor moving said looper from its normal, path including a lever, a platemounted movably on said lever, means operated through said plate forlocking said actuating means against mo'vement, means for moving saidplate upon said lever, and means for limiting the-movement upon thelever of said plate. v In testimony whereof, I' have signed my nametothis specification.

ALBERT H. DE VOE.

